7-Zip is an open source file archiver with the high compression ratio predominantly for the Microsoft Windows operating system. It operates either as a command line program or with a graphical userinterface. It also features integration with the Windows shell environment. 7-Zip is free software, developed by Igor Pavlov and distributed under the GNU LGPL license. For ZIP and GZIP formats, 7-Zip provides a compression ratio that is 2-10 % better than the ratio provided by PKZip and WinZip.